Poster Presentations: P1 P181
with APP695 by Co-Immunoprecipitation with HSP56, HSP70, and
UBQLN1 antibodies suggesting that these chaperones are associated with
APP695. Conclusions: In summary, we conclude that HSP56, HSP70,
and UBQLN1 may play a direct role in the in the folding of APP695 and
may be useful in therapeutic uses for degradation of Amyloid-b.
P1-079 BETA-AMYLOID–INDUCED NEUROTOXICITY
MIGHT BE REDUCED THROUGH AMPK-
MEDIATED BY DONEPEZIL
Moon Ho Park1, Kun-Woo Park2, Hyeon Soo Kim3, 1Korea University
Medical College, Seoul, South Korea; 2Korea University Medical College,
Seoul, South Korea; 3Korea University, Seoul, South Korea.
Contact e-mail: [email protected]
Background: Acetylcholinesterase inhibitors (AchEIs) and NMDA recep-
tor anatagonist memantine are used for the treatment of Alzheimer’s dis-
ease. Recently, the AchEI donepezil and memantine were found to have
neuroprotective effects. However, these protective mechanisms have not
yet been clearly identified. AMP-activated protein kinase (AMPK), a master
regulator of cellular energy homeostasis and a central player in glucose and
lipid metabolism, is potentially implicated in the pathogensis of Alzheim-
er’s disease. We investigated the neuroprotective effects of donepezil and
memantine against amyloid-b 1-42 (Ab42)-induced neurotoxicity and
AMPK signal pathway in HN33 hippocampal cell line.Methods: The neu-
roprotective effects of treatment with donepezil andmemantine on Ab42-in-
duced cell death, was measured by MTT assay. Expression levels of
phosphorylation status of AMPK were analyzed by Western blot. Intracel-
lular calcium concentration was measured with calcium indicator dye,
fluo-3AM. Results:We reported that only donepezil increased intracellular
calcium concentration and donepezil activated AMPK in HN33 cells with
Ab42. Moreover, inhibition of AMPK resulted in blockage of donepezil-in-
duced calcium uptake. Conclusions: These results suggest that donepezil
might prevent Ab42-induced neurotoxicity through AMPK pathway.
P1-080 TIME-COURSE OF BEHAVIORAL AND
L-ARGININEMETABOLIC PROFILE CHANGES IN
THE APP SWE PS1 DE9 MOUSE MODEL OF
ALZHEIMER’S DISEASE
David Bergin1, Yu Jing1, Hu Zhang2, BruceMockett3,Wickliffe Abraham1,
Ping Liu1, 1University of Otago, Dunedin, New Zealand; 2School of
Pharmacy, University of Otago, Dunedin, New Zealand; 3Department of
Psychology, University of Otago, Dunedin, New Zealand.
Contact e-mail: [email protected]
Background: Alzheimer’s disease (AD) is a common neurodegenerative
disease among the elderly. Due to complicated idiopathic pathology, AD
is best characterized by progressive cognitive decline with memory loss
as the earliest prognostic indicator. Mounting evidence indicates that L-ar-
ginine metabolism - integral for cell homeostasis, growth and memory - is
altered in AD. However L-arginine metabolism has not been investigated
in transgenic (Tg) animal models that are used to mimic and understand
pathological AD processes. Methods: The current study examined the be-
havioral and L-arginine metabolic profile in 7 and 13 month old male
APP SWE PS1 DE9 mice using both reference and working memory ver-
sions of the Morris water maze task, high-performance liquid chromatogra-
phy and liquid chromatography mass spectroscopy. Results:We found that
7 month old Tg mice demonstrated mild impairments in spatial working
memory, increased agmatine in the parahippocampal cortex, and increased
spermine concentrations in the frontal cortex and striatum compared to their
wild-type littermates. At 13 months of age, Tg mice were significantly im-
paired in both versions of the watermaze task and had accompanying alter-
ations in L-arginine, L-ornithine, agmatine, putrescine, spermidine or
spermine in at least one of the five brain regions examined. There were
no genotype-specific differences in the cerebellum at either age. Nor were
there genotype specific differences in glutamate or GABA at either age
points in any brain region. Conclusions: These results indicate that L-argi-
nine metabolism is increasingly altered with age in the APP SWE PS1 DE9
mice, which reflect and may influence the behavioral impairments observed.
P1-081 IDENTIFICATION OFAN ALTERNATIVE APP
PROCESSING PATHWAY
Michael Willem1, Sabina Tahirovic2, Ignasi Forn�e3, Elisabeth Kremmer4,
Christiane Volbracht5, H�el�ene Marie6, Christian Haass7, 1University
Munich, Munich, Germany; 2DZNE-M€unchen, Munich, Germany;3Adolf-Butenandt-Institute, Munich, Germany; 4Hemholtz-Center Munich,
Munich, Germany; 5Lundbeck, Copenhagen, Denmark; 6IPMC-CNRS
UMR7275, Sophia-Antipolis, France; 7DZNE & LMU Munich, Munich,
Germany. Contact e-mail: [email protected]
Background:Generation of amyloid b -peptide (Ab) from the amyloid pre-
cursor protein (APP) depends on sequential cleavage by b - and b -secretase.
The aspartylprotease BACE1 (b -site APP cleaving enzyme-1) is known to
be the sole b-secretase in the brain, based on the complete absence of b-sec-
retase cleavage products in BACE1 -/- mice and massively reduced Ab
levels in mouse brains upon treatment with a BACE1 inhibitor. Methods:
We investigated APP processing in the absence of BACE1 activity upon
pharmacological inhibition and siRNA knock down in CHO cells and pri-
mary neurons. For in vivo analysis, we used brain lysates of BACE1 KO
mice and inhibitor treated animals. Epitope specific monoclonal antibodies
were produced and applied for biochemical identification of APP processing
products, e.g. by SEC and LC-MS/MS analysis.Results: Biochemical anal-
ysis revealed that pharmacological blockade of b-secretase, results not only
in reduction of A b synthesis but also in accumulation of novel APP-C-ter-
minal fragments. The fragments generated in the absence of BACE1 are N-
terminally extended, which could be demonstrated with specific antibodies
directed against this region.We identified and characterized a corresponding
secreted fragment in supernatants of APP expressing. A similar cleavage
pattern is observed in primary neuronal cultures and in mouse brain where
it is enriched upon BACE1 blockade. Conclusions: With these studies we
identified new APP cleavage products which could potentially influence
not only A b production but also Ab toxicity.
P1-082 TYROSINE KINASE INHIBITION PROMOTES
PARKIN-BECLIN-1–MEDIATED PROTECTION IN
ALZHEIMER’S DISEASE MODELS
Irina Lonskaya, Michaeline Hebron, Charbel Moussa, Georgetown
University, Washington, D.C., United States. Contact e-mail: cem46@
georgetown.edu
Background: The tyrosine kinase c-Abl is activated in neurodegenerative
disorders, including Alzheimer’s disease (AD). Nilotinib is a c-Abl inhibitor
approved by the U.S. Food and Drug Administration (FDA) for treatment of
adult leukemia.We evaluated the effects of Nilotinib on c-Abl inhibition and
autophagic clearance of b-amyloid and Tau in models of AD.Methods:We
injected mice IP with 10mg/kg Nilotinib once a day for 3consecutive weeks
and performed several biochemical, histological and behavioral tests to
evaluate Nilotinib effects on amyoid clearance and cognition. Results: Pe-
ripheral administration of Nilotinib inhibited c-Abl and other tyrosine kin-
asesand resulted in activation of the E3 ubiquitin ligase parkin, and elevation
of beclin-1 in AD mice brain. Nilotinib-mediated parkin activation stimu-
lated the autophagic clearance pathway, leading to amyloid degradation
and cognitive improvement in a parkin-dependent manner. Nilotinib failed
to clear autophagic vacuoles and amyloid proteins in parkin -/- mice, despite
an increase in beclin-1 levels, whereas beclin-1 knockdown attenuated A
b clearance, underscoring an indispensable role for endogenous parkin in
autophagy. These data suggest that Nilotinib-mediated c-Abl inhibition is
a therapeutic strategy to rescue cells from intraneuronal amyloid toxicity
and prevent both plaque deposition and progression frommild cognitive im-
pairment to AD.Conclusions:Although no parkin mutations are associated
with AD, parkin manipulation may be a disease modifying therapy that pro-
vides an alternative approach to prevent progression from MCI to AD. Ni-
lotinib is FDA approved, re-purposing its use is not only useful for MCI
treatment but were it to be effective, it also could be used to test the validity
of disease biomarkers such as p-Tau and b -amyloid. These studies provide
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